There is a demand for marking of lines, arranged at a more or less high altitude above the ground, visually, that is to say with marking bodies, in order to make these lines visible for air vehicles like aircraft and helicopters. Telephone lines, supporting steel wires etc. may be mentioned. Firstly lines and wires of the type mentioned introductorily are considered.
Until now it has been very expensive to clamp up such marking bodies on lines at high altitudes. This is especially true for ground wires for transfer systems for 400 kV or 800 kV electricity, which in many cases comprise wires in terrain that is difficult to access, or over sea bays, fiords and lakes.